diff --git a/backend/internal/service/pay.go b/backend/internal/service/pay.go
index 218c622..9d4effd 100644
--- a/backend/internal/service/pay.go
+++ b/backend/internal/service/pay.go
@@ -9,6 +9,7 @@ import (
 	"net/http"
 	"strconv"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/google/uuid"
@@ -19,8 +20,7 @@ import (
 	"github.com/wangjia/jiu/backend/internal/util"
 )
 
-// PayService jiu ↔ pay 收款中枢对接（下单/查单已切 pay v2 契约 /api/v2/orders，
-// webhook 回调仍为 v1 契约，见 HandleCallback）。
+// PayService jiu ↔ pay 收款中枢对接：下单/查单/webhook 均为 pay v2 契约。
 // 四块职责：下单（CreatePurchase）、webhook 入账（HandleCallback）、续期（entitle）、查单兜底（reconcileOnce）。
 type PayService struct {
 	db      *gorm.DB
@@ -28,6 +28,9 @@ type PayService struct {
 	secret  string
 	retURL  string
 	client  *http.Client
+
+	seenMu sync.Mutex           // 保护 seen（nonce 防重放，单实例内存实现）
+	seen   map[string]time.Time
 }
 
 var (
@@ -208,18 +211,21 @@ func (s *PayService) signedPost(path string, rawBody []byte) ([]byte, error) {
 
 // ---------- ② webhook 入账 ----------
 
+// payNotification pay v2 webhook payload（无 trade_no 字段，事件以 event_type 为准，
+// X-Pay-Event 头不参与签名不依赖）。
 type payNotification struct {
+	EventType      string `json:"event_type"`
 	OutTradeNo     string `json:"out_trade_no"`
 	BizSystem      string `json:"biz_system"`
 	BizRef         string `json:"biz_ref"`
 	ProductBizCode string `json:"product_biz_code"`
-	Amount         string `json:"amount"`
-	TradeNo        string `json:"trade_no"`
+	AmountMinor    int64  `json:"amount_minor"`
+	Currency       string `json:"currency"`
 	Channel        string `json:"channel"`
 	PaidAt         string `json:"paid_at"`
 }
 
-// HandleCallback 验签 + 幂等 + 金额核对 + 续期。错误分两类：
+// HandleCallback 验签 + 时间窗 + nonce 防重放 + 按 event_type 分发。错误分两类：
 // ErrPaySignature（回 401，不重试也无效）；其余（回非 SUCCESS，pay 会重试）。
 func (s *PayService) HandleCallback(rawBody []byte, ts, nonce, sign string) error {
 	if !s.Configured() {
@@ -235,6 +241,9 @@ func (s *PayService) HandleCallback(rawBody []byte, ts, nonce, sign string) erro
 	if d := time.Since(time.Unix(tsInt, 0)); d > 5*time.Minute || d < -5*time.Minute {
 		return ErrPaySignature
 	}
+	if s.replayed(nonce) {
+		return ErrPaySignature
+	}
 
 	var n payNotification
 	if err := json.Unmarshal(rawBody, &n); err != nil || n.OutTradeNo == "" {
@@ -244,12 +253,39 @@ func (s *PayService) HandleCallback(rawBody []byte, ts, nonce, sign string) erro
 	if t, err := time.Parse(time.RFC3339, n.PaidAt); err == nil {
 		paidAt = t
 	}
-	return s.settle(n.OutTradeNo, n.ProductBizCode, n.Amount, n.TradeNo, n.Channel, paidAt)
+	switch n.EventType {
+	case "payment.succeeded":
+		return s.settle(n.OutTradeNo, n.ProductBizCode, n.AmountMinor, n.Currency, n.Channel, paidAt)
+	default: // refund.*/未来事件：本期不接（另起任务）；ack 防 60s 永久重投，ALERT 留痕
+		log.Printf("[pay] ALERT unhandled webhook event=%s out_trade_no=%s (acked)", n.EventType, n.OutTradeNo)
+		return nil
+	}
 }
 
-// settle 入账：幂等（同 out_trade_no 只续一次）+ 金额核对 + 同事务续期。
+// replayed nonce 防重放：10 分钟窗口内重复即拒绝（pay 合法重投每次生成新 nonce 不受影响；
+// 单实例内存实现，重启丢失由 settle 幂等兜底）。
+func (s *PayService) replayed(nonce string) bool {
+	s.seenMu.Lock()
+	defer s.seenMu.Unlock()
+	now := time.Now()
+	for k, t := range s.seen {
+		if now.Sub(t) > 10*time.Minute {
+			delete(s.seen, k)
+		}
+	}
+	if _, ok := s.seen[nonce]; ok {
+		return true
+	}
+	if s.seen == nil {
+		s.seen = map[string]time.Time{}
+	}
+	s.seen[nonce] = now
+	return false
+}
+
+// settle 入账：幂等（同 out_trade_no 只续一次）+ 金额核对（残单先兜底回填）+ 同事务续期。
 // webhook 与查单兜底共用此入口。
-func (s *PayService) settle(outTradeNo, bizCode, amount, tradeNo, channel string, paidAt time.Time) error {
+func (s *PayService) settle(outTradeNo, bizCode string, amountMinor int64, currency, channel string, paidAt time.Time) error {
 	var shopID uint64
 	err := s.db.Transaction(func(tx *gorm.DB) error {
 		var p model.LicensePurchase
@@ -263,8 +299,17 @@ func (s *PayService) settle(outTradeNo, bizCode, amount, tradeNo, channel string
 		if p.Status == "paid" { // 幂等：pay 会重发
 			return nil
 		}
-		if !amountEqual(p.Amount, amount) {
-			log.Printf("[pay] amount mismatch out_trade_no=%s purchase=%s callback=%s", outTradeNo, p.Amount, amount)
+		if p.AmountMinor == 0 { // D1 残单兜底：下单后回填失败，入账前补查权威价
+			if st, qerr := s.queryOrder(outTradeNo); qerr == nil && st.AmountMinor > 0 {
+				p.AmountMinor, p.Currency = st.AmountMinor, st.Currency
+				if err := tx.Model(&model.LicensePurchase{}).Where("id = ?", p.ID).
+					Updates(map[string]any{"amount_minor": p.AmountMinor, "currency": p.Currency}).Error; err != nil {
+					return err
+				}
+			}
+		}
+		if amountMinor != p.AmountMinor || !strings.EqualFold(currency, p.Currency) {
+			log.Printf("[pay] amount mismatch out_trade_no=%s purchase=%d/%s callback=%d/%s", outTradeNo, p.AmountMinor, p.Currency, amountMinor, currency)
 			return ErrPayAmount
 		}
 		// 权益按建单时的套餐映射；回调 biz_code 仅一致性校验（不一致以本地为准并告警）
@@ -291,18 +336,20 @@ func (s *PayService) settle(outTradeNo, bizCode, amount, tradeNo, channel string
 				log.Printf("[pay] ALERT promo double-claim out_trade_no=%s shop=%d：本店已享受过首月特惠，本单不叠加时长", outTradeNo, p.ShopID)
 			}
 		}
+		updates := map[string]any{
+			"status":  "paid",
+			"channel": channel,
+			"paid_at": paidAt,
+		}
 		if entitleOK {
-			if err := entitle(tx, p.ShopID, plan); err != nil {
+			renewedTo, err := entitle(tx, p.ShopID, plan)
+			if err != nil {
 				return err
 			}
+			updates["renewed_to"] = renewedTo
 		}
 		shopID = p.ShopID
-		return tx.Model(&model.LicensePurchase{}).Where("id = ?", p.ID).Updates(map[string]any{
-			"status":   "paid",
-			"trade_no": tradeNo,
-			"channel":  channel,
-			"paid_at":  paidAt,
-		}).Error
+		return tx.Model(&model.LicensePurchase{}).Where("id = ?", p.ID).Updates(updates).Error
 	})
 	if err != nil {
 		return err
@@ -316,8 +363,9 @@ func (s *PayService) settle(outTradeNo, bizCode, amount, tradeNo, channel string
 }
 
 // entitle 给门店续期：时长直接叠加（未过期从到期日叠，已过期从现在起算），
-// 并写入套餐权益。逻辑对齐 LicenseService.Redeem 的叠加段。
-func entitle(tx *gorm.DB, shopID uint64, plan payPlan) error {
+// 并写入套餐权益。逻辑对齐 LicenseService.Redeem 的叠加段。返回续期后的授权到期日
+// （settle 落库 renewed_to 展示用）。
+func entitle(tx *gorm.DB, shopID uint64, plan payPlan) (time.Time, error) {
 	now := time.Now()
 	var lic model.License
 	err := tx.Set("gorm:query_option", "FOR UPDATE").
@@ -325,7 +373,7 @@ func entitle(tx *gorm.DB, shopID uint64, plan payPlan) error {
 		Order("id DESC").First(&lic).Error
 	creating := errors.Is(err, gorm.ErrRecordNotFound)
 	if err != nil && !creating {
-		return err
+		return time.Time{}, err
 	}
 
 	base := now
@@ -345,16 +393,22 @@ func entitle(tx *gorm.DB, shopID uint64, plan payPlan) error {
 			MaxDevices: plan.MaxDevices,
 			Features:   plan.Features,
 		}
-		return tx.Create(&lic).Error
+		if err := tx.Create(&lic).Error; err != nil {
+			return time.Time{}, err
+		}
+		return expires, nil
 	}
-	return tx.Model(&lic).Updates(map[string]any{
+	if err := tx.Model(&lic).Updates(map[string]any{
 		"type":        plan.Type,
 		"tier":        plan.Tier,
 		"expires_at":  expires,
 		"is_active":   true,
 		"max_devices": plan.MaxDevices,
 		"features":    plan.Features,
-	}).Error
+	}).Error; err != nil {
+		return time.Time{}, err
+	}
+	return expires, nil
 }
 
 // BackfillPurchaseAmountMinor 启动回填：v1 存量购买单 amount("2999.00") → amount_minor(299900)+CNY。
@@ -372,13 +426,6 @@ func BackfillPurchaseAmountMinor(db *gorm.DB) {
 	}
 }
 
-// amountEqual 金额按分归一比较（"2999.00" == "2999" == "2999.0"）。
-func amountEqual(a, b string) bool {
-	ca, ea := toCents(a)
-	cb, eb := toCents(b)
-	return ea == nil && eb == nil && ca == cb
-}
-
 func toCents(s string) (int64, error) {
 	s = strings.TrimSpace(s)
 	if s == "" {
@@ -493,7 +540,7 @@ func (s *PayService) reconcileOnce() {
 			if st.PaidAt != nil {
 				paidAt = *st.PaidAt
 			}
-			if err := s.settle(p.OutTradeNo, p.ProductBizCode, formatMinor(st.AmountMinor), "", "", paidAt); err != nil {
+			if err := s.settle(p.OutTradeNo, p.ProductBizCode, st.AmountMinor, st.Currency, "", paidAt); err != nil {
 				log.Printf("[pay] reconcile settle failed out_trade_no=%s: %v", p.OutTradeNo, err)
 			} else {
 				log.Printf("[pay] reconcile settled out_trade_no=%s (webhook missed)", p.OutTradeNo)
diff --git a/backend/internal/service/pay_test.go b/backend/internal/service/pay_test.go
index e2ea7f8..992211e 100644
--- a/backend/internal/service/pay_test.go
+++ b/backend/internal/service/pay_test.go
@@ -9,6 +9,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/google/uuid"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"gorm.io/gorm"
@@ -24,31 +25,39 @@ func newTestPaySvc(db *gorm.DB, baseURL string) *PayService {
 	return NewPayService(db, baseURL, testPaySecret, "https://jiu.example.com/license/result/")
 }
 
-// signedCallbackArgs 按契约给回调体生成签名参数（模拟 pay 侧签名）。
+// signedCallbackArgs 按契约给回调体生成签名参数（模拟 pay 侧签名）。每次调用生成新 nonce，
+// 模拟 pay 合法重投（每次重投重新生成 nonce/sign）；原样重放请复用同一次的返回值。
 func signedCallbackArgs(body []byte) (ts, nonce, sign string) {
 	ts = strconv.FormatInt(time.Now().Unix(), 10)
-	nonce = "test-nonce"
+	nonce = uuid.New().String()
 	sign = util.PaySign(testPaySecret, "jiu", ts, nonce, string(body))
 	return
 }
 
-func callbackBody(outTradeNo, bizCode, amount string) []byte {
+// eventBody 构造 pay v2 webhook payload（无 trade_no 字段）。
+func eventBody(eventType, outTradeNo, bizCode string, amountMinor int64, currency string) []byte {
 	b, _ := json.Marshal(map[string]any{
+		"event_type":       eventType,
 		"out_trade_no":     outTradeNo,
 		"biz_system":       "jiu",
 		"biz_ref":          "1",
 		"product_biz_code": bizCode,
-		"amount":           amount,
-		"trade_no":         "2026070322001",
+		"amount_minor":     amountMinor,
+		"currency":         currency,
 		"channel":          "alipay",
 		"paid_at":          time.Now().Format(time.RFC3339),
 	})
 	return b
 }
 
-func createPendingPurchase(t *testing.T, db *gorm.DB, shopID uint64, bizCode, amount, otn string) *model.LicensePurchase {
+// callbackBody 便捷封装：event_type 固定 payment.succeeded、currency 固定 CNY。
+func callbackBody(outTradeNo, bizCode string, amountMinor int64) []byte {
+	return eventBody("payment.succeeded", outTradeNo, bizCode, amountMinor, "CNY")
+}
+
+func createPendingPurchase(t *testing.T, db *gorm.DB, shopID uint64, bizCode string, amountMinor int64, currency, otn string) *model.LicensePurchase {
 	t.Helper()
-	p := &model.LicensePurchase{ShopID: shopID, UserID: 1, ProductBizCode: bizCode, Amount: amount, OutTradeNo: otn, Status: "pending"}
+	p := &model.LicensePurchase{ShopID: shopID, UserID: 1, ProductBizCode: bizCode, AmountMinor: amountMinor, Currency: currency, OutTradeNo: otn, Status: "pending"}
 	require.NoError(t, db.Create(p).Error)
 	return p
 }
@@ -64,21 +73,12 @@ func TestPaySign_Vector(t *testing.T) {
 	assert.False(t, util.PaySignVerify("other", got, "jiu", "1751520000", "nonce", `{"a":1}`))
 }
 
-func TestAmountEqual(t *testing.T) {
-	assert.True(t, amountEqual("2999.00", "2999"))
-	assert.True(t, amountEqual("2999.0", "2999.00"))
-	assert.True(t, amountEqual("0.01", "0.01"))
-	assert.False(t, amountEqual("2999.00", "2999.01"))
-	assert.False(t, amountEqual("", "2999"))
-	assert.False(t, amountEqual("abc", "2999"))
-}
-
 // ---------- 回调：验签门 ----------
 
 func TestHandleCallback_BadSignature(t *testing.T) {
 	db := testutil.SetupTestDB()
 	svc := newTestPaySvc(db, "http://pay.invalid")
-	body := callbackBody("yanmei-1", "annual_standard", "2999.00")
+	body := callbackBody("yanmei-1", "annual_standard", 299900)
 	ts, nonce, _ := signedCallbackArgs(body)
 
 	err := svc.HandleCallback(body, ts, nonce, "forged-signature")
@@ -88,7 +88,7 @@ func TestHandleCallback_BadSignature(t *testing.T) {
 func TestHandleCallback_ExpiredTimestamp(t *testing.T) {
 	db := testutil.SetupTestDB()
 	svc := newTestPaySvc(db, "http://pay.invalid")
-	body := callbackBody("yanmei-1", "annual_standard", "2999.00")
+	body := callbackBody("yanmei-1", "annual_standard", 299900)
 	ts := strconv.FormatInt(time.Now().Add(-10*time.Minute).Unix(), 10)
 	sign := util.PaySign(testPaySecret, "jiu", ts, "n", string(body))
 
@@ -99,20 +99,80 @@ func TestHandleCallback_ExpiredTimestamp(t *testing.T) {
 func TestHandleCallback_NotConfigured(t *testing.T) {
 	db := testutil.SetupTestDB()
 	svc := NewPayService(db, "http://pay.invalid", "", "")
-	body := callbackBody("yanmei-1", "annual_standard", "2999.00")
+	body := callbackBody("yanmei-1", "annual_standard", 299900)
 	ts, nonce, sign := signedCallbackArgs(body)
 	assert.ErrorIs(t, svc.HandleCallback(body, ts, nonce, sign), ErrPaySignature)
 }
 
+// TestHandleCallback_NonceReplay：同一 ts/nonce/sign 原样重发（非 pay 合法重投，
+// 合法重投每次生成新 nonce）→ 拒签。
+func TestHandleCallback_NonceReplay(t *testing.T) {
+	db := testutil.SetupTestDB()
+	shop := testutil.CreateTestShop(db, "PAY013")
+	createPendingPurchase(t, db, shop.ID, "annual_standard", 299900, "CNY", "yanmei-otn-replay")
+
+	svc := newTestPaySvc(db, "http://pay.invalid")
+	body := callbackBody("yanmei-otn-replay", "annual_standard", 299900)
+	ts, nonce, sign := signedCallbackArgs(body)
+	require.NoError(t, svc.HandleCallback(body, ts, nonce, sign))
+
+	err := svc.HandleCallback(body, ts, nonce, sign)
+	assert.ErrorIs(t, err, ErrPaySignature, "原样重放应拒签")
+}
+
+// TestHandleCallback_UnknownEventAcked：refund.* 等本期不接的事件应 ack（返回 nil）防
+// pay 60s 永久重投，且不改变购买单状态。
+func TestHandleCallback_UnknownEventAcked(t *testing.T) {
+	db := testutil.SetupTestDB()
+	shop := testutil.CreateTestShop(db, "PAY014")
+	createPendingPurchase(t, db, shop.ID, "annual_standard", 299900, "CNY", "yanmei-otn-refund")
+
+	svc := newTestPaySvc(db, "http://pay.invalid")
+	body := eventBody("refund.succeeded", "yanmei-otn-refund", "annual_standard", 299900, "CNY")
+	ts, nonce, sign := signedCallbackArgs(body)
+	assert.NoError(t, svc.HandleCallback(body, ts, nonce, sign), "未知事件应 ack")
+
+	var p model.LicensePurchase
+	require.NoError(t, db.Where("out_trade_no = ?", "yanmei-otn-refund").First(&p).Error)
+	assert.Equal(t, "pending", p.Status, "未知事件不改变购买单状态")
+}
+
+// TestHandleCallback_ResidualAmountBackfill：残单兜底——建单时金额回填失败（amount_minor=0），
+// 入账前补查权威价成功 → 核对通过并回填。
+func TestHandleCallback_ResidualAmountBackfill(t *testing.T) {
+	db := testutil.SetupTestDB()
+	shop := testutil.CreateTestShop(db, "PAY015")
+	createPendingPurchase(t, db, shop.ID, "annual_standard", 0, "", "yanmei-otn-residual")
+
+	mux := http.NewServeMux()
+	mux.HandleFunc("GET /api/v2/orders/yanmei-otn-residual", func(w http.ResponseWriter, r *http.Request) {
+		fmt.Fprint(w, `{"data":{"order_no":"yanmei-otn-residual","status":"paid","amount_minor":299900,"currency":"CNY"}}`)
+	})
+	payServer := httptest.NewServer(mux)
+	defer payServer.Close()
+
+	svc := newTestPaySvc(db, payServer.URL)
+	body := callbackBody("yanmei-otn-residual", "annual_standard", 299900)
+	ts, nonce, sign := signedCallbackArgs(body)
+	require.NoError(t, svc.HandleCallback(body, ts, nonce, sign))
+
+	var p model.LicensePurchase
+	require.NoError(t, db.Where("out_trade_no = ?", "yanmei-otn-residual").First(&p).Error)
+	assert.Equal(t, "paid", p.Status)
+	assert.Equal(t, int64(299900), p.AmountMinor, "残单兜底应回填金额")
+	assert.Equal(t, "CNY", p.Currency)
+	assert.NotNil(t, p.RenewedTo, "入账应落库续期后到期日")
+}
+
 // ---------- 回调：入账 ----------
 
 func TestHandleCallback_SettleAndRenew(t *testing.T) {
 	db := testutil.SetupTestDB()
 	shop := testutil.CreateTestShop(db, "PAY001")
-	createPendingPurchase(t, db, shop.ID, "annual_standard", "2999.00", "yanmei-otn-1")
+	createPendingPurchase(t, db, shop.ID, "annual_standard", 299900, "CNY", "yanmei-otn-1")
 
 	svc := newTestPaySvc(db, "http://pay.invalid")
-	body := callbackBody("yanmei-otn-1", "annual_standard", "2999.00")
+	body := callbackBody("yanmei-otn-1", "annual_standard", 299900)
 	ts, nonce, sign := signedCallbackArgs(body)
 	require.NoError(t, svc.HandleCallback(body, ts, nonce, sign))
 
@@ -121,6 +181,7 @@ func TestHandleCallback_SettleAndRenew(t *testing.T) {
 	assert.Equal(t, "paid", p.Status)
 	assert.Equal(t, "alipay", p.Channel)
 	assert.NotNil(t, p.PaidAt)
+	assert.NotNil(t, p.RenewedTo, "入账应落库续期后到期日")
 
 	var lic model.License
 	require.NoError(t, db.Where("shop_id = ?", shop.ID).Order("id DESC").First(&lic).Error)
@@ -129,15 +190,16 @@ func TestHandleCallback_SettleAndRenew(t *testing.T) {
 	assert.Equal(t, 2, lic.MaxDevices)
 	assert.InDelta(t, 365, daysFromNow(lic.ExpiresAt), 1)
 	assert.Equal(t, float64(1000), lic.Features["image_quota"]) // JSON 数字解出 float64
+	assert.True(t, p.RenewedTo.Equal(*lic.ExpiresAt), "renewed_to 应等于续期后的授权到期日")
 }
 
 func TestHandleCallback_Idempotent(t *testing.T) {
 	db := testutil.SetupTestDB()
 	shop := testutil.CreateTestShop(db, "PAY002")
-	createPendingPurchase(t, db, shop.ID, "monthly_pro", "599.00", "yanmei-otn-2")
+	createPendingPurchase(t, db, shop.ID, "monthly_pro", 59900, "CNY", "yanmei-otn-2")
 
 	svc := newTestPaySvc(db, "http://pay.invalid")
-	body := callbackBody("yanmei-otn-2", "monthly_pro", "599.00")
+	body := callbackBody("yanmei-otn-2", "monthly_pro", 59900)
 	ts, nonce, sign := signedCallbackArgs(body)
 	require.NoError(t, svc.HandleCallback(body, ts, nonce, sign))
 
@@ -148,7 +210,7 @@ func TestHandleCallback_Idempotent(t *testing.T) {
 		expires1 = *lic.ExpiresAt
 	}
 
-	// pay 重发同一单：不得重复续期
+	// pay 重发同一单：新 nonce/sign（合法重投特征），不得重复续期
 	ts2, nonce2, sign2 := signedCallbackArgs(body)
 	require.NoError(t, svc.HandleCallback(body, ts2, nonce2, sign2))
 	var lic model.License
@@ -159,10 +221,10 @@ func TestHandleCallback_Idempotent(t *testing.T) {
 func TestHandleCallback_AmountMismatch(t *testing.T) {
 	db := testutil.SetupTestDB()
 	shop := testutil.CreateTestShop(db, "PAY003")
-	createPendingPurchase(t, db, shop.ID, "annual_pro", "5999.00", "yanmei-otn-3")
+	createPendingPurchase(t, db, shop.ID, "annual_pro", 599900, "CNY", "yanmei-otn-3")
 
 	svc := newTestPaySvc(db, "http://pay.invalid")
-	body := callbackBody("yanmei-otn-3", "annual_pro", "0.01") // 篡改金额
+	body := callbackBody("yanmei-otn-3", "annual_pro", 599899) // 差 1 分
 	ts, nonce, sign := signedCallbackArgs(body)
 	assert.ErrorIs(t, svc.HandleCallback(body, ts, nonce, sign), ErrPayAmount)
 
@@ -174,7 +236,7 @@ func TestHandleCallback_AmountMismatch(t *testing.T) {
 func TestHandleCallback_UnknownOrder(t *testing.T) {
 	db := testutil.SetupTestDB()
 	svc := newTestPaySvc(db, "http://pay.invalid")
-	body := callbackBody("yanmei-not-exist", "annual_standard", "2999.00")
+	body := callbackBody("yanmei-not-exist", "annual_standard", 299900)
 	ts, nonce, sign := signedCallbackArgs(body)
 	assert.ErrorIs(t, svc.HandleCallback(body, ts, nonce, sign), ErrPurchaseNotFound)
 }
@@ -190,10 +252,10 @@ func TestEntitle_StackOnActiveLicense(t *testing.T) {
 		ShopID: shop.ID, LicenseKey: "SEED-1", Type: "trial", Tier: "standard",
 		ExpiresAt: &future, IsActive: true, MaxDevices: 3,
 	}).Error)
-	createPendingPurchase(t, db, shop.ID, "annual_standard", "2999.00", "yanmei-otn-4")
+	createPendingPurchase(t, db, shop.ID, "annual_standard", 299900, "CNY", "yanmei-otn-4")
 
 	svc := newTestPaySvc(db, "http://pay.invalid")
-	body := callbackBody("yanmei-otn-4", "annual_standard", "2999.00")
+	body := callbackBody("yanmei-otn-4", "annual_standard", 299900)
 	ts, nonce, sign := signedCallbackArgs(body)
 	require.NoError(t, svc.HandleCallback(body, ts, nonce, sign))
 
@@ -211,10 +273,10 @@ func TestEntitle_ExpiredStartsFromNow(t *testing.T) {
 		ShopID: shop.ID, LicenseKey: "SEED-2", Type: "trial", Tier: "standard",
 		ExpiresAt: &past, IsActive: true, MaxDevices: 3,
 	}).Error)
-	createPendingPurchase(t, db, shop.ID, "monthly_standard", "299.00", "yanmei-otn-5")
+	createPendingPurchase(t, db, shop.ID, "monthly_standard", 29900, "CNY", "yanmei-otn-5")
 
 	svc := newTestPaySvc(db, "http://pay.invalid")
-	body := callbackBody("yanmei-otn-5", "monthly_standard", "299.00")
+	body := callbackBody("yanmei-otn-5", "monthly_standard", 29900)
 	ts, nonce, sign := signedCallbackArgs(body)
 	require.NoError(t, svc.HandleCallback(body, ts, nonce, sign))
 
@@ -334,13 +396,13 @@ func TestCreatePurchase_PromoOncePerShop(t *testing.T) {
 	assert.NotErrorIs(t, err, ErrPromoUsed)
 
 	// pending 单不算已享用（可能弃单），仍可重新下单
-	createPendingPurchase(t, db, shop.ID, PromoBizCode, "1.00", "yanmei-promo-0")
+	createPendingPurchase(t, db, shop.ID, PromoBizCode, 100, "CNY", "yanmei-promo-0")
 	used, err = svc.PromoUsed(shop.ID)
 	require.NoError(t, err)
 	assert.False(t, used, "pending 不算已享用")
 
 	// 已支付的特惠单存在 → 已享用，再购直接拒绝
-	p := createPendingPurchase(t, db, shop.ID, PromoBizCode, "1.00", "yanmei-promo-1")
+	p := createPendingPurchase(t, db, shop.ID, PromoBizCode, 100, "CNY", "yanmei-promo-1")
 	require.NoError(t, db.Model(p).Update("status", "paid").Error)
 	used, err = svc.PromoUsed(shop.ID)
 	require.NoError(t, err)
@@ -362,10 +424,10 @@ func TestHandleCallback_PromoDoubleClaimNoEntitle(t *testing.T) {
 	svc := newTestPaySvc(db, "http://pay.invalid")
 
 	// 并发双买：两笔 pending 特惠单同时存在，先后收到回调
-	createPendingPurchase(t, db, shop.ID, PromoBizCode, "1.00", "yanmei-promo-a")
-	createPendingPurchase(t, db, shop.ID, PromoBizCode, "1.00", "yanmei-promo-b")
+	createPendingPurchase(t, db, shop.ID, PromoBizCode, 100, "CNY", "yanmei-promo-a")
+	createPendingPurchase(t, db, shop.ID, PromoBizCode, 100, "CNY", "yanmei-promo-b")
 
-	body := callbackBody("yanmei-promo-a", PromoBizCode, "1.00")
+	body := callbackBody("yanmei-promo-a", PromoBizCode, 100)
 	ts, nonce, sign := signedCallbackArgs(body)
 	require.NoError(t, svc.HandleCallback(body, ts, nonce, sign))
 
@@ -375,7 +437,7 @@ func TestHandleCallback_PromoDoubleClaimNoEntitle(t *testing.T) {
 	assert.InDelta(t, 30, daysFromNow(lic.ExpiresAt), 1, "第一笔正常续期 30 天")
 
 	// 第二笔回调：标 paid 但不再叠加
-	body2 := callbackBody("yanmei-promo-b", PromoBizCode, "1.00")
+	body2 := callbackBody("yanmei-promo-b", PromoBizCode, 100)
 	ts2, nonce2, sign2 := signedCallbackArgs(body2)
 	require.NoError(t, svc.HandleCallback(body2, ts2, nonce2, sign2), "回调须回 SUCCESS，pay 停止重试")
 
@@ -387,8 +449,8 @@ func TestHandleCallback_PromoDoubleClaimNoEntitle(t *testing.T) {
 	assert.True(t, lic.ExpiresAt.Equal(expires1), "第二笔特惠单不得叠加时长")
 
 	// 兜底只限特惠：同店正常套餐单不受影响
-	createPendingPurchase(t, db, shop.ID, "monthly_standard", "299.00", "yanmei-normal-c")
-	body3 := callbackBody("yanmei-normal-c", "monthly_standard", "299.00")
+	createPendingPurchase(t, db, shop.ID, "monthly_standard", 29900, "CNY", "yanmei-normal-c")
+	body3 := callbackBody("yanmei-normal-c", "monthly_standard", 29900)
 	ts3, nonce3, sign3 := signedCallbackArgs(body3)
 	require.NoError(t, svc.HandleCallback(body3, ts3, nonce3, sign3))
 	require.NoError(t, db.Where("shop_id = ?", shop.ID).Order("id DESC").First(&lic).Error)
@@ -401,7 +463,7 @@ func TestStatus_ScopedToShop(t *testing.T) {
 	db := testutil.SetupTestDB()
 	shop := testutil.CreateTestShop(db, "PAY007")
 	other := testutil.CreateTestShop(db, "PAY008")
-	createPendingPurchase(t, db, shop.ID, "annual_standard", "2999.00", "yanmei-otn-7")
+	createPendingPurchase(t, db, shop.ID, "annual_standard", 299900, "CNY", "yanmei-otn-7")
 
 	svc := newTestPaySvc(db, "http://pay.invalid")
 	st, err := svc.Status(shop.ID, "yanmei-otn-7")
@@ -414,14 +476,23 @@ func TestStatus_ScopedToShop(t *testing.T) {
 
 // ---------- v2 金额回填 ----------
 
+// createLegacyAmountPurchase 建一条只有 v1 元字符串 amount、amount_minor=0 的存量购买单，
+// 供 BackfillPurchaseAmountMinor 测试其从旧列回填。
+func createLegacyAmountPurchase(t *testing.T, db *gorm.DB, shopID uint64, bizCode, amount, otn string) *model.LicensePurchase {
+	t.Helper()
+	p := &model.LicensePurchase{ShopID: shopID, UserID: 1, ProductBizCode: bizCode, Amount: amount, OutTradeNo: otn, Status: "pending"}
+	require.NoError(t, db.Create(p).Error)
+	return p
+}
+
 func TestBackfillPurchaseAmountMinor(t *testing.T) {
 	db := testutil.SetupTestDB()
 	shop := testutil.CreateTestShop(db, "PAY012")
 
-	p1 := createPendingPurchase(t, db, shop.ID, "annual_standard", "2999.00", "yanmei-backfill-1")
-	p2 := createPendingPurchase(t, db, shop.ID, PromoBizCode, "1.00", "yanmei-backfill-2")
+	p1 := createLegacyAmountPurchase(t, db, shop.ID, "annual_standard", "2999.00", "yanmei-backfill-1")
+	p2 := createLegacyAmountPurchase(t, db, shop.ID, PromoBizCode, "1.00", "yanmei-backfill-2")
 	// 已有 amount_minor>0 的行不应被覆盖
-	p3 := createPendingPurchase(t, db, shop.ID, "monthly_pro", "599.00", "yanmei-backfill-3")
+	p3 := createLegacyAmountPurchase(t, db, shop.ID, "monthly_pro", "599.00", "yanmei-backfill-3")
 	require.NoError(t, db.Model(p3).Updates(map[string]any{"amount_minor": 123, "currency": "USD"}).Error)
 
 	BackfillPurchaseAmountMinor(db)